Method of forming dental plates



(No Model.)

M. R. GRISWOLD. METHOD 0F PCRD/[ING DENTAL PLATES.

Patented 1360.15, 1891.

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UNITED STATES PATENT EEICE.

MALCOLM R. cRIswOLD, or HARTFORD, CONNECTICUT.

METHOD OF FORMING DENTAL. PLATES.

SYECIFICATION forming part of' Letters Patent No. 465,076, dated December 15, 1891.

Application filed February 5, 1891. ASerial No.330,384. (No model.)

To all whom, it' may concern:

Beit known that I, MALCOLM R. GRIswoLD, of Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Methods of Making Plates for Artificial Teeth, of which the following is a full, clear, and exact description, whereby any one skilled in the art can make and use the same.

My invention relates to the art of manufacturing plates for false teeth and to the use of dental liasks for such a purpose; and my object is to provide a flask and a method of using thesame by means of which a more perfect result in production of the plate and teeth attached thereto in the act of vulcanizingcan be obtained.

To this end my invention consists in the method of making the plate and the building up of the same preparatory to vulcanization and in details of the method or process, as more particularly hereinafter described, and pointed out in the claim.

Referring to the drawings, Figure l is a plan view of the bottoni section of a dental flask, as filled with a molded form. Fig. 2 is a detail plan view of the lower side of the middle section. Fig. 3 is a detail plan view of the under side of the upper section, also filled. Fig. et is a detail view in cross-section on plane ce .r of Fig. l. Fig. 5 is a detail view in cross-section on plane y y of Fig. 2. Fig. (i is a detail View in central cross-section of the flask and contents, as secured together in proper manner preparatory to vulcanizing the plate. Fig. 7 is a detail face view of the flask-locking means. Fig. S is a detail View in section of the flask adjacent to the locking device. Fig. 9 is a view showing a modified form of fastening device.

In the accompanying drawings, the letter a denotes a dental flask as a whole, that is composed, usuallyof metal cast to shape.

l) denotes the bottom section, c the middle section, and d the upper section, of the flask, the utilization of the new feature-that is, the middle section c-in connection with the other parts, forming the main feature of my withindescribed invention.

In the ordinary flask com posed of two parts, after a cast has been taken of the mouth,the flask is filled with a mass of plasterofparis or like material, forming a mold that conforms in shape precisely to the outline of the cast made of the mouth. Such flasks have been made in two parts, the lower part containing all that is included in the sections b and c of my improved form, while the upper section includes what is embodied in the upper section of my improved form. lVhen such a two-part flask of the old art has been used, the pink rubber used to make the gum has been packed into the mold about the teeth c, and then the central portion, forming the roof or main portion of the plate, is next packed into the mold and the upper part closed down upon it, the result being that the black rubber in this closing of the flask and in the act of vulcanization is forced through the mass of rubber and presents an unsightly appearance along the front of the teeth, dcstroying in a great measure the desired effeet, which is the perfect imitation of the natural gum.

By the method employed of separating the flask into three sections I rst pack the groove fin the lower flask with the india rubber. Then place the middle section c, that contains the teeth, over the bottom section b, (in a reverse position from that shown in Fig. 2 of the drawings.) Then pack the black rubber over the top directly upon the central portion of the mold that forms the main portion ofthe tooth-plate. 'Ihen the upper section is placed upon the middle section and the several sections are securely clamped together in any desired manner. Then so clamped the flask is placed in the vulcanizer and treated in the ordinary manner for producing the rubber set.

The several parts or sections of the flask may be clamped together by means of a leg g on one part that extends into a socketh on the opposite part, this socket being preferably formed between projections h', cast upon the outer body partof the section, and in one of these legs there is formed a screw-socket t', in which a clamping-screw t" is located. In one edge of the leg g there is a locking-socket g', semicircular in outline, and the clampingscrew t" is mutilated on one side, so as to allow the leg g, when the screw is turned in a certainposition, to enter the socket h, and the sections may then be securely clamped IOO dle section of the mold containing the teeth over the lower section, then packing into the flask containing the inold the rubber that forms the main portion of the tooth-plate, then placing the upper section upon the middle section and clamping the several parts securely together, and then vulcanizing the plate in the usual manner, all substantially as described.

MALCOLM R. GRISVOLD.

Witnesses:

LEONARD C. DANIELS, A. B. JENKINS. 

